point

Pointing is the process of filling, packing, and finishing the mortar joints between bricks, stones, or concrete blocks in a completed wall. After the initial mortar has set, a worker uses a trowel to pack fresh mortar firmly into the joint, then shapes and compresses it to create a weathertight seal and finished appearance. This is distinct from the initial laying of mortar during wall construction, where joints are left slightly recessed or rough to receive pointing work later.

The mortar used for pointing is often slightly different from the bed mortar used during construction. It may contain a higher proportion of cement for durability, or lime for older masonry that requires softer, more flexible joints. The joint itself is raked out (cleaned of loose material) to a depth of 2.5 to 5 centimetres before new mortar is forced in. The timing matters: pointing cannot begin until the wall has gained sufficient strength but before the underlying mortar hardens completely and becomes impossible to work around.

Joint profiles and finish

Pointing produces several standard joint profiles. Flush joints are smoothed level with the face of the wall. Weathered joints are angled to shed water downward. Recessed joints are compressed inward, creating shadow lines for visual effect but leaving small shelves where water can collect. Struck joints are angled outward, generally the weakest profile for weathertightness. The choice affects both aesthetics and performance; on masonry exposed to heavy rain or freeze-thaw cycling, flush or weathered joints outperform recessed or struck profiles.

Mortar colour and composition in pointing can differ from the original wall, either intentionally for effect or because materials change over decades. Repointing (pointing existing joints that have failed) requires matching the original mortar colour and strength as closely as possible. Using mortar that is too hard or too stiff compared to the surrounding units can cause spalling and damage. In historical masonry, matching mortar is critical; a hard modern cement mortar can cause softer original brickwork to fail.

Poor pointing work allows water to penetrate through joints, leading to frost damage, efflorescence, and structural decay. Pointing that is done too soon, before the wall has cured, or on mortar that is too dry or too wet tends to crack and fail quickly. The skill lies in judging the right moment, preparing the joint properly, applying firm pressure, and finishing the profile evenly. On large projects, pointing is labour-intensive and represents a significant portion of overall masonry cost.